Dictation that does not sound dictated
Spoken prose has tells. Most of them are fixable, and one of them is worth keeping.
Writers who try dictation usually give up for the same reason: the transcript reads like someone talking, because it is. Long run-on sentences, "sort of" and "you know", every paragraph starting with "And so". It looks like a first draft written by someone worse than you.
Almost all of that comes from dictating the way you talk rather than the way you write, and it is a habit rather than a limit.
Dictate a paragraph, not a chapter
The biggest single improvement. Speaking for twenty minutes produces speech; speaking one paragraph produces prose. A paragraph is short enough to hold whole in your head, so you can shape it before you start and hear it as a unit while you say it.
It also makes the result reviewable. A paragraph you can compare against what was there before. Twenty minutes of transcript you will not read carefully, and you know it.
Know the sentence before you start it
Run-ons happen when you begin talking and work out where you are going on the way. Pause, decide how the sentence ends, then say it. The silence feels awkward and costs nothing; nobody is waiting.
Do not dictate punctuation
Saying "comma" and "full stop" splits your attention between the prose and the typography, and it is the fastest way to sound mechanical. Speak in whole sentences with natural pauses and let the cleanup pass put in the commas. That is what it is for.
Dialogue is the exception worth knowing: it helps to pause slightly before and after a spoken line, so the shape is unambiguous.
Revising is easier than drafting
If dictation has not worked for you, it may be that you tried it for the wrong job. Producing new prose out loud is genuinely hard. Replacing a paragraph you have just heard fail is much easier, because the target is defined: you know what the paragraph has to do, you know what the old one got wrong, and you only have to beat something that already exists.
Most writers who dictate comfortably arrived through revision rather than drafting.
The tell worth keeping
Dictated prose is more speakable. Sentences come out at breath length, dialogue sounds like people, and the rhythm is the rhythm of a voice rather than of a hand. That is not a flaw to be edited out; for fiction it is most of what you were trying to achieve.
Keep it, and remove only the filler around it.
Check the result
Transcription is very good and not perfect, and it is worst exactly where your book is most itself: invented names, places, coined words. Filling in a codex helps, because the names can be handed to the transcriber. Read the new paragraph before you accept it. In Qlemi nothing replaces your text until you do.